Add Milano Centrale (XIMB, 8300046).

Source: https://github.com/trainline-eu/stations/blob/master/stations.csv via https://public.opendatasoft.com/explore/dataset/european-train-stations/information/

Thanks to @marudor for pointing it out

This also extends the station names

Both are useful to determine which sub-station a departure belongs to when
using with_related => 1.